The overall objective of the proposed research effort is to continue work towards determining the optimum care for children with all types of cancer. The research mechanism involves participation by pediatric investigators at the Bowman Gray School of Medicine in the development and execution of collaborative multidisciplinary clinical protocols of the pediatric Oncology Group. The proposed research grant will support the continued participation of the Bowman Gray School of Medicine as a full member of the pediatric Oncology Group. Our accomplishments in the past grant period are described in detail in the proposal. Our institutional goals for the five year period of this grant include: (1) continuing our high level of patient accrual and excellent clinical contributions to the POG including our outstanding patient evaluability and protocol compliance which has merited a letter of commendation from the operations office at every 6-month analysis in the past (2) maintaining our institutional involvement in POG leukemia studies and our representation on the new ALL core committee (3) continuation and further development of our multi-disciplinary institutional commitment to POG Hodgkin's disease activities (4) a major role on the POG cytogenetics committee including optimal use of our new reference laboratory status (5) increased institutional development of late effects studies in collaboration with the POG late effects efforts (6) expansion of our efforts in neuro-oncology including increased enrollment on brain tumor studies and investigator roles on the POG brain tumor committee (7) use of in situ studies of tumor cell ploidy in collaboration with POG and other investigators (8) continued contributions to the administrative aspects of the POG.